CN101938850B

CN101938850B - Method, system and device for releasing bearer resources

Info

Publication number: CN101938850B
Application number: CN 200910088166
Authority: CN
Inventors: 习建德; 赵国胜
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: China Academy of Telecommunications Technology CATT; Datang Mobile Communications Equipment Co Ltd
Priority date: 2009-07-03
Filing date: 2009-07-03
Publication date: 2013-07-24
Anticipated expiration: 2029-07-03
Also published as: CN103024931A; CN101938850A; CN103024931B

Abstract

The invention discloses a method, a system and a device for releasing bearer resources. The method comprises that: in a detachment initiating process, a triggering entity transmits a bearer deletion request message comprising a reason for bearer deletion to a service gateway; after receiving the bearer deletion request message, the service gateway deactivates an ISR mode and deletes bearer context related to the triggering entity if determining that local detachment is required according to the reason for the bearer deletion; and if determining complete detachment is required according to the reason for the bearer deletion, the service gateway deactivates the ISR mode and transmits a bearer deletion request to a PDN gateway to trigger the PDN gateway to execute a bearer deletion process. The method has the advantages of effectively deleting a bearer, reducing hops of signaling through which a control plane triggers a control plane to release the bearer, and improving the reliability of the process.

Description

Method, system and device for releasing bearing resources

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method, a system, and an apparatus for releasing bearer resources.

Background

In the third generation partnership project (3GPP) Evolved Packet System (EPS) system, in order to simplify the movement of a User Equipment (UE) between an evolved universal Terrestrial Radio Access Network (E-UTRAN) and a Universal Terrestrial Radio Access Network (UTRAN)/GPRS Enhanced Radio Access Network (GERAN), a mechanism for simplifying signaling in an Idle mode, i.e., Idle Signaling Reduction (ISR), is proposed, which means that a Mobility Management Entity (MME) serving the E-UTRAN manages location information of the UE when the UE initially registers to the E-UTRAN, and only a Routing Area Update (route) procedure needs to be performed to a serving GPRS Support node when the UE moves to an old system UTRAN/GERAN in the Idle mode, while the MME on the E-UTRAN side still maintains the context information of the UE. This enables location updating in a simplified signalling manner when the UE moves between such two access systems in idle mode without the need for an attach procedure at the target system.

Under the ISR mechanism, the serving gateway (S-GW) serving the MME and the SGSN also needs to maintain an ISR activation flag, and determine to maintain corresponding bearer resources to the MME and/or the SGSN according to the ISR activation flag. The HSS is dual registered when ISR is activated, i.e. the MME registers with the Home Subscriber Server (HSS), and the SGSN also registers with the HSS.

The following is the MME-Initiated detach procedure (MME-Initiated detach procedure) in the prior art.

Step 101: the MME triggers the detach procedure, which may specifically be to trigger implicit detach or explicit detach.

Such as: if the UE does not interact with the network side within a certain time, the MME may trigger implicit detach, and in this case, the MME does not send a detach request message to the UE, and performs an implicit detach procedure locally at the MME, for example: registration information in one SGSN is not detached.

The MME may detach the UE by sending an explicit detach request message to the UE if the UE is in the ECM-connected state.

Step 102: the MME sends a delete bearer request message containing the TEID to the S-GW to deactivate the UE associated with the S-GW and any EPS bearer context information in the relevant MME. If the PDNGW requires location information of the UE, the MME may also further include user location information in the sent delete bearer request message.

Step 103: when S-GW receives the first delete bearer request message from MME in ISR activation state, S-GW deactivates ISR, releases EPS bearer context information related to MME, and responds to delete bearer response message, wherein the delete bearer response message includes TEID.

When the S-GW receives the delete bearer request message from the MME or the SGSN in the ISR deactivated state, the S-GW releases the related EPS bearer context information, and performs step 6, sending a bearer delete request message to the PDN GW. After step 7, the S-GW sends a bearer deletion response message to the MME/SGSN.

Step 104: if the mobile terminal is in the ISR activated state, the MME sends a detach indication message to the associated SGSN, wherein the detach indication message contains the International Mobile Subscriber Identity (IMSI) and the detach reason. The reason for the detach is used to indicate whether to detach locally or fully.

Step 105: if the detach cause indicates complete detach, the SGSN sends a delete bearer request message containing the TEID to the S-GW. If the detach cause indicates local detach, the SGSN will deactivate ISR and proceed to step 109. If the PDN GW requires location information of the UE, the SGSN may also further include user location information in the sent delete bearer request message.

Step 106: if ISR is in activated state, S-GW deactivates ISR and sends a delete bearer request message containing TEID to PDN GW.

Step 107: and the PDN GW feeds back a bearer deletion response message to the S-GW, wherein the bearer deletion response message contains the TEID.

Step 108: and an IP-CAN session termination process is executed between the PDN GW and the PCRF.

Step 109: and the S-GW feeds back a bearer deletion response message to the SGSN, wherein the bearer deletion response message contains the TEID.

Step 110: and after receiving the bearer deletion response message, the SGSN sends a detachment indication confirmation message to the MME.

Step 111: if the UE receives the detach request message transmitted in step 101 from the MME, the UE transmits a detach accept message to the MME at any time after step 101.

Step 112: after receiving the detach accept message sent in step 111, the delete bearer response sent in step 103, or further receiving the detach indication confirm message sent in step 110, the MME sends S1-MME signaling connection for releasing the UE, and S1 release command (cause) message to the evolved base station (eNodeB). If the detach type requires the UE to establish a new attach, the UE re-attaches after the RRC connection release is complete.

Step 113: after the MME receives the delete bearer response from the serving gateway, if the subscription data indicates that the user is allowed to perform a transfer to a non-3 GPP access and the MME is configured to notify the HSS to detach, the MME will send an advertisement request indicating that the HSS will remove the APN and pdn gw identity corresponding to the UE in pairs.

Step 114: and the HSS removes the stored APN and PDN GW identification corresponding to the UE in pairs and sends a notification response to the MME.

The above procedure is a detach procedure initiated by the MME, and the detach procedure initiated by the SGSN is similar to the trigger procedure initiated by the MME, but the trigger entities are different, and are not described here again.

In the 3GPP EPS system, in ISR active mode, the S-GW maintains bearer resources to both E-UTRAN and UTRAN/GERAN. Under the UE detach situation, taking the detach procedure initiated by the MME as an example, when the triggering entity triggers detach, there are several problems:

(1) if the MME initiates implicit detach, the MME notifies the S-GW to deactivate EPS bearer context information related to the MME in step 102, and notifies the SGSN to perform local detach in step 104.

In this way, after the S-GW performs local detach, the ISR flag is deactivated, and only the EPS bearer context information related to the MME is deleted, but the EPS bearer context information related to the SGSN is also saved. Therefore, if the UE re-attaches to the MME, or the UE re-attaches to the MME without successfully detaching to the SGSN, and the MME has the subscription context information of the UE, the SGSN is not triggered by the HSS to delete the old bearer resource, and in this case, how to delete the resource in the SGSN, how to delete the bearer resource on the S-GW, can enable the UE to successfully attach again.

The reason why the MME has the subscription context information of the UE is as follows: as the result of the detach is that the MME or SGSN deletes the resource information related to the bearer without deleting the subscription information of the UE, this subscription information is generally deleted only through a Purge (Purge) procedure sent to the HSS by the MME/SGSN after being stored for a long time, so as to reduce the load of the HSS.

(2) If the MME initiates explicit detach, the MME notifies the S-GW to delete the EPS bearer context information related to the MME in step 102, deactivates ISR, and notifies the SGSN of its complete detach in step 104.

The SGSN informs the S-GW to delete the EPS bearer resources associated with the SGSN in step 105 based on the complete detach indication. There is a risk here: if the message of deleting the Bearer Request from the SGSN to the S-GW is blocked, and after the UE re-attaches the Request to the MME after detach, and the MME initiates a Request for establishing a Default Bearer (Create Default Bearer Request) to the S-GW, if the APN corresponding to the Default Bearer (Default Bearer) is the same as the APN corresponding to the original Bearer, the creation of the Default Bearer will definitely fail, and the UE cannot successfully re-attach.

In summary, in the prior art, under the ISR activation condition, the bearer resource cannot be effectively released.

Disclosure of Invention

The invention provides a method, a system and a device for releasing bearing resources, which are used for solving the problem that the bearing resources can not be effectively released under the condition of ISR activation in the prior art.

The method for releasing the bearing resource provided by the embodiment of the invention comprises the following steps:

in the process of initiating detachment, a trigger entity sends a bearer deletion request message to a service gateway, wherein the bearer deletion request message contains reason information of bearers needing to be deleted;

after receiving the request message for deleting the bearer, if the service gateway determines that local detachment is needed according to the reason information for deleting the bearer, the service gateway deactivates the ISR mode and deletes the bearer context related to the triggering entity;

and if the complete detachment is determined to be required according to the reason information for the load deletion, the service gateway deactivates the ISR mode, initiates a load deletion request to the PDN gateway and triggers the PDN gateway to execute a load deletion process.

The system for releasing the bearing resource provided by the embodiment of the invention comprises:

the trigger entity is used for sending a bearer deletion request message to the service gateway, wherein the bearer deletion request message contains the reason information of the bearer to be deleted;

the service gateway is used for deactivating an ISR mode and deleting the bearer context related to the triggering entity if the local detachment is determined to be needed according to the reason information of the bearer needing to be deleted after receiving the bearer deleting request message; and if the complete detachment is determined to be required according to the reason information for the bearer to be deleted, deactivating the ISR mode, initiating a bearer deletion request to the PDN gateway, and triggering the PDN gateway to execute a bearer deletion process.

An embodiment of the present invention provides a gateway device, including:

a receiving unit, configured to receive a bearer deletion request message from a trigger entity, where the bearer deletion request message includes cause information that a bearer needs to be deleted;

a local detach unit, configured to, after receiving the bearer deletion request message, if it is determined that local detach is required according to the cause information of the bearer that needs to be deleted, deactivate an ISR mode, and delete a bearer context related to the trigger entity;

and a complete detach unit, configured to deactivate an ISR mode, initiate a request for deleting a bearer to the PDN gateway, and trigger the PDN gateway to perform a bearer deletion process if it is determined that complete detach is required according to the cause information for deleting a bearer.

The network device provided by the embodiment of the invention comprises:

a configuration unit, configured to configure a bearer deletion request message containing cause information for a bearer to be deleted;

and the first sending unit is used for sending the bearer deletion request message to the service gateway.

after receiving an attachment request of UE, a triggering entity sends a bearer deletion request message containing UE TEID to an associated gateway and triggers a PDN gateway to execute an IP-CAN session termination process if the subscription context information of the UE does not contain a last implicit detach type and an ISR activation activity mark when determining that the subscription context information of the UE exists;

if the subscription context information of the UE contains the last implicit detach type and the ISR activation activity mark, a location updating request is sent to the HSS, the HSS is informed to send a location deleting message to the ISR activated related node entity which does not execute detach, and all bearing information of the UE is deleted.

The embodiment of the invention provides a network device, which comprises:

a receiving unit, configured to receive an attach request of a UE;

a query determining unit, configured to determine whether subscription context information of the UE exists after receiving an attach request of the UE;

a first execution unit, configured to, when subscription context information of the UE exists, send a bearer deletion request message containing a TEID of the UE to an associated gateway if the subscription context information of the UE does not contain a last implicit detach type and an ISR activation activity flag, and trigger a PDN gateway to execute an IP-CAN session termination process;

a second execution unit, configured to, when the subscription context information of the UE exists, if the subscription context information of the UE contains a last implicit detach type and an ISR activation activity flag, initiate a location update request to the HSS, notify the HSS to send a location deletion message to a relevant node entity that is not activated by the ISR that performs detach, and delete all bearer information of the UE.

In the method, in the process of initiating detachment, a trigger entity sends a bearer deletion request message to a service gateway, wherein the bearer deletion request message contains reason information of bearers needing to be deleted; after receiving the request message for deleting the bearer, if the service gateway determines that local detachment is needed according to the reason information for deleting the bearer, the service gateway deactivates the ISR mode and deletes the bearer context related to the triggering entity; and if the complete detachment is determined to be required according to the reason information for the bearer to be deleted, the service gateway initiates a bearer deletion request to the PDN gateway and executes a bearer deletion process. The method shortens the hop number Hops of the signaling for the control plane to trigger the user plane to carry out the bearer release, and improves the reliability of the process.

In addition, in the embodiment of the present invention, after the triggering entity receives the attach request of the UE, when it is determined that the subscription context information of the UE exists, if the subscription bearer context information of the UE does not contain the last implicit detach type and ISR activation activity flag, a bearer deletion request message containing the TEID of the UE is sent to the associated gateway, and the PDN gateway is triggered to execute the IP-CAN session termination process; if the type of the last implicit detach and the ISR activation activity mark are contained, a location updating request is sent to the HSS, the HSS is informed to send a location deleting message to the ISR activated related node entity which does not execute the detach, all bearing information of the UE is deleted, and the UE can be ensured to be successfully reattached after the implicit detach.

Drawings

FIG. 1 is a schematic flow chart of MME-initiated detach in the prior art;

fig. 2 is a flowchart of a method for deleting bearer resources during an attach procedure under ISR activation according to an embodiment of the present invention;

FIG. 3 is a flowchart illustrating a detach procedure initiated by an MME according to an embodiment of the present invention;

FIG. 4 is a flow chart illustrating a detach procedure initiated by an SGSN according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a system according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a network device corresponding to the triggering entity in the embodiment shown in fig. 5;

FIG. 7 is a schematic structural diagram of a network device corresponding to the serving gateway in the embodiment shown in FIG. 5;

fig. 8 is a flowchart illustrating a process of deleting an original bearer resource of a UE in a UE reattachment process according to an embodiment of the present invention;

fig. 9 is a schematic diagram of a specific process for implementing UE attachment according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a network device corresponding to the triggering entity in the embodiment shown in fig. 8.

Detailed Description

In the embodiment of the invention, in the process of initiating detachment, the bearer deletion request message sent to the service gateway by the triggering entity contains the reason information of the bearer to be deleted; after receiving the request message for deleting the bearer, if the service gateway determines that local detachment is needed according to the reason information for deleting the bearer, the service gateway deactivates the ISR mode and deletes the bearer context related to the triggering entity; and if the complete detachment is determined to be required according to the reason information for the bearer to be deleted, the service gateway initiates a bearer deletion request to the PDN gateway and executes a bearer deletion process.

Referring to fig. 2, a method for deleting bearer resources under an ISR activation condition in an embodiment of the present invention includes the following steps:

step 201: in the process of initiating detachment, a trigger entity sends a bearer deletion request message to a service gateway, wherein the bearer deletion request message contains reason information of bearers needing to be deleted;

step 202: after receiving the request message for deleting the bearer, the serving gateway determines the type of the attachment to be performed according to the reason information for deleting the bearer, if it is determined that local detachment is required, step 203 is performed, and if it is determined that complete detachment is required, step 204 is performed;

step 203: the service gateway deactivates the ISR mode, deletes the bearing context related to the triggering entity and ends the process;

step 204: the service gateway initiates a request for deleting the bearer to the PDN gateway, executes the process of deleting the bearer, and ends the flow.

In step 204, the serving gateway sends a request for deleting bearer to the PDN gateway, and after receiving the request for deleting bearer, the PDN gateway executes an IP-CAN session termination procedure to delete the bearer resource of the UE.

Here, further, in the process of initiating detach, the triggering entity may send a detach indication to the relevant node entity activated by the ISR, where the detach indication contains the reason information that the bearer needs to be deleted; after the relevant node entity activated by ISR receives the detach indication, if the local detach is determined to be needed according to the reason information of the bearer to be deleted, the ISR mode is deactivated, and if the complete detach is determined to be needed according to the reason information of the bearer to be deleted, the locally stored context information of the UE is deleted; and the related node entity activated by the ISR responds a response message to the triggering entity. Here, before, after, or simultaneously with step 201, the triggering entity may send a detach indication to the relevant node entity activated by the ISR.

If the detach process is local detach, the service gateway can further store the detach type and the latest ISR activation activity mark, which is used to provide the location update request process to HSS when the UE attaches the trigger entity of local detach last time, and trigger HSS to initiate location cancel process to the ISR activated related node entity.

The triggering entity is MME or SGSN, and the ISR activated related node entity is SGSN or MME. Such as: when the triggering entity is MME, the ISR activated related node entity is SGSN; when the triggering entity is SGSN; and the ISR activated related node entity is MME.

The following describes the technical solutions of the present invention respectively when the triggering entity is an MME or when the triggering entity is an SGSN. Figure 3 illustrates an example of bearer resource deletion with MME-initiated detach. Referring to fig. 3, the specific implementation procedure of MME-initiated detach is as follows:

step 301: the MME triggers the detach procedure, which may specifically be to trigger implicit detach or explicit detach.

Step 302: the MME sends a delete bearer request message to the S-GW, which contains the TEID and the reason for deleting the bearer, to deactivate the UE associated with the S-GW and any EPS bearer context information in the related MME. If the PDN GW requires location information of the UE, the MME may also further include user location information in the sent delete bearer request message. Wherein the reason for deleting the bearer is used to indicate local detach or complete detach.

Step 303: if ISR is in activated state, S-GW receives the request message for deleting load, if the reason in the request message for deleting load indicates local detachment, ISR is deactivated, and EPS load context information associated with MME is released; and if the reason in the bearer deletion request message indicates complete detachment, releasing the EPS bearer context information associated with the MME, and sending a bearer deletion request message containing the TEID to the PDN GW. In the ISR deactivation state, after receiving the request message for deleting the bearing, the S-GW releases the related EPS bearing context information and sends a bearing deletion request message to the PDN GW.

Step 304: after receiving the request message for deleting the bearer, the PDN GW feeds back a response message for deleting the bearer, which contains the TEID, to the S-GW.

Step 305: and an IP-CAN termination process is executed between the PDN GW and the PCRF.

Step 306: and in the ISR activated state, after receiving the bearer deletion response message, the S-GW responds the bearer deletion response message to the MME, wherein the bearer deletion response message comprises the TEID.

Step 307: if ISR is in activated state, MME sends detach indication to SGSN after receiving delete load response message, which contains IMSI and detach reason. The reason for the detach is used to indicate whether to detach locally or fully.

Step 308: if the UE is completely detached, the SGSN deletes the locally stored context information of the UE, and if the UE is locally detached, the ISR mark is deactivated. The SGSN sends a detach indication acknowledgement message to the MME.

Step 309: if the UE receives the detach request message transmitted in step 101 from the MME, the UE transmits a detach accept message to the MME at any time after step 101.

Step 310: after receiving the detach accept message, the delete bearer response, or further receiving the detach indication confirm message, the MME sends an S1-MME signaling connection releasing the UE, and an S1 release command (cause) message to an evolved nodeb (eNodeB). If the detach type requires the UE to establish a new attach, the UE re-attaches after the RRC connection release is complete.

Step 311: after the MME receives the delete bearer response from the serving gateway, if the subscription data indicates that the user is allowed to perform a transfer to a non-3 GPP access and the MME is configured to notify the HSS to detach, the MME will send an advertisement request indicating that the HSS will remove the APN and pdn gw identity corresponding to the UE in pairs.

Step 312: and the HSS removes the stored APN and PDN GW identification corresponding to the UE in pairs and sends a notification response to the MME.

Fig. 4 is an example of SGSN terminating bearer resources with an initiated detach indication. Referring to fig. 4, the specific implementation procedure of the SGSN-initiated detach is as follows:

step 401: the SGSN triggers the detach process, which may specifically be implicit detach triggering or explicit detach triggering.

Such as: if the UE does not interact with the network side within a certain time, the SGSN may trigger implicit detach, and in this case, the SGSN does not send a detach request message to the UE, and performs an implicit detach process locally at the SGSN, for example: registration information in one MME is not detached.

If the UE is in PMM-CONNECTED state, the SGSN can detach the UE by sending an explicit detach request message to the UE.

Step 402: the SGSN sends a delete bearer request message to the S-GW with the TEID and reason for deleting the bearer to deactivate the UE associated with the S-GW and any EPS bearer context information in the relevant SGSN. If the PDN GW requires location information of the UE, the SGSN may also further include user location information in the sent delete bearer request message. Wherein the reason for deleting the bearer is used to indicate local detach or complete detach.

Step 403: if ISR is in activated state, S-GW receives the request message for deleting load, if the reason in the request message for deleting load indicates local detachment, ISR is deactivated, and EPS load context information associated with SGSN is released; if the reason in the bearer deletion request message indicates complete detachment, the EPS bearer context information associated with the SGSN is released, and a bearer deletion request message containing the TEID is sent to the PDN GW.

If ISR is in activated state, S-GW receives the request message for deleting load, then deactivates ISR, releases EPS load context information associated with MME, and sends a request message for deleting load containing TEID to PDN GW. If the reason in the delete bearer request message indicates local detach, the S-GW releases only the bearer context associated with the MME and does not send the delete bearer request message to the pdn GW.

In the ISR deactivation state, after receiving the request message for deleting the bearing, the S-GW releases the related EPS bearing context information and sends a bearing deletion request message to the PDN GW.

Step 404: after receiving the request message for deleting the bearer, the PDN GW feeds back a response message for deleting the bearer, which contains the TEID, to the S-GW.

Step 405: and an IP-CAN session termination process is executed between the PDN GW and the PCRF.

Step 406: in ISR activated state, S-GW receives the response message of bearing, and then responds the response message of deleting bearing to SGSN, wherein the response message includes TEID.

Step 407: if ISR is in activated state, SGSN sends detach indication to MME after receiving delete load response message, which contains IMSI and detach reason. The reason for the detach is used to indicate whether to detach locally or fully.

Step 408: and if the UE is completely detached, the MME deletes the locally stored context information of the UE, and if the UE is locally detached, the ISR mark is deactivated. The MME sends a detach indication acknowledgement message to the SGSN.

Step 409: if the UE receives the detach request message sent in step 401 from the SGSN, the UE sends a detach accept message to the SGSN at any time after step 401.

Step 410: after receiving the detach accept message, deleting the bearer response, or further receiving the detach indication confirm message, the SGSN sends a PS signaling connection releasing the UE. If the detach type requires the UE to establish a new attach, the UE re-attaches after the RRC connection release is complete.

Step 411: after the SGSN receives the delete bearer response from the serving gateway, if the subscription data indicates that the user is allowed to perform a transfer to a non-3 GPP access and the SGSN is configured to notify the HSS to detach, the SGSN will send a notification request indicating that the HSS will remove the APN and PDN GW identities corresponding to the UE in pairs.

Step 412: and the HSS removes the stored APN and PDN GW identification corresponding to the UE in pairs and sends a notification response to the SGSN.

Referring to fig. 5, a system for releasing bearer resources according to an embodiment of the present invention includes: a triggering entity 51 and a service gateway 52. Wherein,

a triggering entity 51, configured to send a bearer deletion request message to a serving gateway, where the bearer deletion request message includes cause information that the bearer needs to be deleted;

the service gateway 52 is configured to deactivate the ISR mode and delete the bearer context related to the trigger entity if it is determined that local detach is required according to the reason information that the bearer needs to be deleted after receiving the bearer deletion request message; and if the complete detachment is determined to be required according to the reason information for the bearer to be deleted, deactivating the ISR mode, initiating a bearer deletion request to the PDN gateway, and triggering the PDN gateway to execute a bearer deletion process.

The system still further includes: the ISR activated relevant node entity 53, the triggering entity is further configured to send a detach indication to the ISR activated relevant node entity, where the detach indication contains the reason information that the bearer needs to be deleted;

the ISR-activated related node entity 53, configured to, after receiving the detach indication, deactivate an ISR flag if it is determined that local detach is required according to the reason information that the bearer needs to be deleted, and delete locally stored context information of the UE if it is determined that complete detach is required according to the reason information that the bearer needs to be deleted; and responding to the response message to the triggering entity.

The triggering entity 51 further includes: a storage unit, configured to further store a detach type and a latest ISR activation activity flag during a local detach procedure, so as to initiate a location update request procedure to the HSS when the UE attaches to the trigger entity next time, and trigger the HSS to initiate a location cancel procedure to a related node entity activated by the ISR.

When the triggering entity is MME, the related node entity activated by ISR is SGSN;

and when the triggering entity is SGSN, the related node entity activated by the ISR is MME.

Referring to fig. 6, a gateway device according to an embodiment of the present invention includes: a receiving unit 61, a local detach unit 62 and a complete detach unit 63. Wherein,

a receiving unit 61, configured to receive a bearer deletion request message from a trigger entity;

a local detach unit 62, configured to, after receiving the bearer deletion request message, if it is determined that local detach is required according to the cause information of the bearer that needs to be deleted, deactivate the ISR mode, and delete the bearer context related to the trigger entity;

and a complete detach unit 63, configured to deactivate the ISR mode, initiate a request for deleting the bearer to the PDN gateway, and trigger the PDN gateway to perform a bearer deletion process if it is determined that complete detach is required according to the cause information for deleting the bearer.

And the complete detach unit 63 initiates a bearer deletion request to the PDN gateway, and executes an IP-CAN session termination procedure.

Referring to fig. 7, a network device according to an embodiment of the present invention includes: a configuration unit 71 and a first sending unit 72. Wherein,

a configuration unit 71, configured to configure a bearer deletion request message containing reason information for requesting bearer deletion;

a first sending unit 72, configured to send the bearer deletion request message to the serving gateway.

Still further include: a second sending unit 73, configured to send a detach indication to the relevant node entity activated by the ISR, where the detach indication includes cause information that the bearer needs to be deleted;

a receiving unit 74, configured to receive a response message from the relevant node entity activated by the ISR.

In addition, for the release process of the bearer resource when the MME (or SGSN) is attached to the implicitly detached MME again after the last time of unsuccessful detach, a specific implementation scheme is given in the embodiment of the present invention, and specific parameters are as shown in the embodiment of fig. 8.

Referring to fig. 8, the process of deleting the original bearer resource of the UE in the UE reattachment process in the embodiment of the present invention is as follows:

step 801: a triggering entity receives an attachment request of UE;

step 802: when determining that the subscription context information of the UE exists, the triggering entity determines whether the subscription context information of the UE contains the last implicit detach type and ISR activation activity flag, if yes, executes step 804, and if not, executes step 803;

step 803: the triggering entity sends a bearer deletion request message containing the UE TEID to the associated gateway, triggers the PDN gateway to execute an IP-CAN session termination process, and ends the process;

step 804: if the subscription context information of the UE contains the last implicit detach type and the ISR activation activity mark, a location updating request is sent to the HSS, the HSS is informed to send a location deleting message to the ISR activated related node entity which does not execute detach, and all bearing information of the UE is deleted.

Referring to fig. 9, a specific process for implementing UE attachment in the embodiment of the present invention is as follows:

step 901: the UE initiates the attach procedure by sending an attach request message to the eNodeB.

The Attach request message includes an International Mobile Subscriber Identity (IMSI) or an old Global Unique Temporary Identity (GUTI), a Tracking Area Identity (TAI) accessed last time (if valid), a UE core network capability, a UE-specified discontinuous reception parameter (DRX), a packet data network Type (PDN Type), a Protocol Configuration Option (PCO), an encrypted Options transmission Flag (encrypted Options transmission Flag), an Attach Type (Attach Type), a Key Set Identity (KSI)_ASME) Non-access stratum sequence number (NAS sequence number), non-access stratum message authentication code (NAS-MAC), appended GUTI, packet domain temporary Mobile subscriber identity signature (P-TMSIsignature).

The method can further comprise the following steps: a Radio Resource Control (RRC) parameter indicating a Selected Network (Selected Network) and an old globally unique MME identification (GUMMEI) parameter.

Step 902-903: the eNodeB determines an MME, forwards the attachment message and the TAI + ECGI identifier of the cell where the UE is located to the new MME together, and executes step 904 after the new MME is successfully authenticated according to the existing flow;

step 904: if there are bearer contexts activated by the UE in the new MME, e.g. the UE re-attaches to the same MME in a situation where it was not previously correctly detached, the new MME deletes these bearer contexts by sending a delete bearer request message to the involved gateways, the request message including a tunnel identification TEID capable of identifying the user. The PDN GW performs an IP Access network IP-can (IP Connectivity Access network) session termination procedure to indicate that bearer resources have been released, if PCRF deployed.

Step 905: if the MME changes since the last detach, or the MME does not have the valid subscription context information of the UE, or the mobile user equipment identity ME identity changes, or the UE provides an IMSI, or the GUTI provided by the UE cannot index to the valid context, or the MME records the implicit detach type and the ISR activation activity mark information recently, the MME sends an Update Location Request (Update Location Request) message to the HSS, wherein the message contains the MME ID, the IMSI, the MEId, the MME capability and the Update type. Wherein the MME capability indicates that the MME supports the regional access restriction function. The update type indicates that this is an attach procedure.

Step 906: the HSS sends a delete Location (Cancel Location) message to the old MME. The message contains the IMSI and the deletion type. The old MME responds to the HSS with a delete Location acknowledgement (Cancel Location Ack) message and deletes the mobility management context and the bearer context. If the update type indicates attach and there is SGSN registration in the HSS, the HSS sends a delete Location (Cancel Location) message to the old SGSN. The message contains the IMSI and the deletion type. The delete type instructs the old MME/SGSN to release the old serving gateway resources.

Step 907: if there are active bearer contexts for the UE in the old MME/SGSN, the old MME/SGSN deletes these bearer contexts by sending a delete bearer request message to the involved gateway. The gateway returns a delete bearer response message to the old MME/SGSN. The message contains a tunnel identification TEID capable of identifying the UE. If the PCRF is deployed, the PDN GW indicates that the bearer resource has been deleted according to the IP-CAN Session Termination procedure (IP-CAN Session Termination) defined by the TS23.203 specification.

Step 908: the HSS replies to the Update Location message of the previous step by sending an Update Location acknowledgement (Update Location Ack) message to the new MME. The response message includes the IMSI and subscriber data. The subscription data includes one or more PDN subscription contexts. Each PDN subscription context contains an EPS Subscribed QoS parameter table (EPS Subscribed QoS Profile) and a subscription APN-based aggregated maximum Bit rate APN-ambr (access Point Name aggregated maximum value index). The new MME verifies the presence of the UE in the new TA. If the subscription check fails due to area subscription or access restrictions, or for other reasons, the new MME rejects the attach request and indicates the appropriate reason, while informing the HSS that the attach procedure is rejected. If all checks are successful, the new MME constructs the context of the UE. If the UE provides APN not allowed for subscription or the HSS rejects the update location procedure, the new MME rejects the attach request for the appropriate reason.

Step 909: the new MME performs the subsequent attach procedure according to the prior art procedure.

Referring to fig. 10, corresponding to the embodiment shown in fig. 8, a network device according to an embodiment of the present invention includes a receiving unit 11, a query determining unit 12, a first executing unit 13, and a second executing unit 14. Wherein,

a receiving unit 11, configured to receive an attach request of a UE;

a query determining unit 12, configured to determine whether subscription context information of the UE exists after receiving an attach request of the UE;

a first executing unit 13, configured to, when the subscription context information of the UE exists, send a bearer deletion request message containing the TEID of the UE to an associated gateway if the subscription context information of the UE does not contain the last implicit detach type and ISR activation activity flag, and trigger the PDN gateway to execute an IP-CAN session termination process;

a second executing unit 14, configured to, when the subscription context information of the UE exists, if the context information of the UE contains the last implicit detach type and ISR activation activity flag, initiate a location update request to an HSS, notify the HSS to send a location deletion message to a relevant node entity that is not activated by the ISR that performs detach, and delete all bearer information of the UE.

In summary, the embodiments of the present invention provide two solutions for bearer release under two situations:

the first method comprises the following steps: in case of ISR activation, in case of MME or SGSN initiating detach, MME or SGSN needs to carry cause of Bearer deletion in a Delete Bearer Request message (Delete Bearer Request) initiated to S-GW, which indicates detach reason, such as: either locally or fully detached. And the SGW deactivates the ISR and determines whether to initiate a bearer deletion request process to the PGW according to the received detach Cause. If the local detach, the S-GW deactivates the ISR and deletes only the bearer context associated with the MME or SGSN sending the delete bearer request message. If the attachment is completely removed, the S-GW initiates a bearer deletion request process to the P-GW to delete the bearer resources. The signaling hop count Hops of the user plane for carrying and releasing triggered by the control plane is shortened, and the reliability of the process is improved.

And the second method comprises the following steps: in case of ISR activation, after an implicit detach is initiated by an MME or SGSN, the associated SGSN or MME is not detached by ISR activation, when the UE is attached to the MME or SGSN which is implicitly detached again, the method for deleting the bearing resources on the S-GW is that the detach type (implicit) and the latest ISR activation activity mark (note: if the UE context is explicitly detached, the detach type and the ISR activation activity mark are not saved) need to be reserved in the UE context saved by the MME or SGSN after the implicit detachment, the MME or SGSN which is implicitly detached according to the recorded implicit detach type and the latest ISR activation activity mark, when the implicit detach and ISR activation activity flag are valid, a Location update request procedure needs to be initiated to the HSS to trigger the HSS to initiate a Cancel Location (Cancel Location) procedure to the SGSN or MME that has not performed the detach, so as to prompt the SGSN or MME to delete the bearer resource on the S-GW.

Through any scheme, the embodiment of the invention can solve the risk that S-GW bearing resources cannot be effectively released when the UE is detached under the condition of ISR activation.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A method for releasing bearer resources, the method comprising:

in the process of initiating detachment, a triggering entity sends a bearer deletion request message containing reason information of the bearer to be deleted to a service gateway;

after receiving the request message for deleting the bearer, if the service gateway determines that local detachment is needed according to the reason information for deleting the bearer, the service gateway deactivates an Idle Signaling Reduction (ISR) mode and deletes the bearer context related to the triggering entity;

and if the complete detachment is determined to be required according to the reason information requiring the bearer deletion, the service gateway deactivates the ISR mode, initiates a bearer deletion request to the packet data network PDN gateway, and triggers the PDN gateway to execute a bearer deletion process.

2. The method of claim 1, wherein in initiating the detach process, the method further comprises:

the triggering entity sends a detachment indication to a related node entity activated by the ISR, wherein the detachment indication contains reason information of the bearer needing to be deleted;

after the relevant node entity activated by ISR receives the detaching indication, if local detaching is determined to be needed according to the reason information of the bearer to be deleted, ISR mark is deactivated, and if complete detaching is determined to be needed according to the reason information of the bearer to be deleted, context information of User Equipment (UE) stored locally is deleted; and the number of the first and second groups,

and the related node entity activated by the ISR responds a response message to the triggering entity.

3. The method of claim 2, wherein the triggering entity is a Mobility Management Entity (MME) or a Serving GPRS Support Node (SGSN);

when the triggering entity is SGSN; and the ISR activated related node entity is MME.

4. The method of claim 1, wherein the performed bearer deletion procedure comprises:

and executing an IP-CAN session termination process between the PDN gateway and the policy charging rule control functional entity PCRF.

5. The method according to claim 2, wherein the step of the triggering entity sending the detach indication to the associated node entity activated by ISR is performed before, after or simultaneously with the step of the triggering entity sending the delete bearer request message to the serving gateway.

6. The method of claim 2 wherein if the detach procedure is local detach, the triggering entity further stores the detach type and a latest ISR activated active flag for providing an update location request procedure to a Home Subscriber Server (HSS) for triggering the HSS to initiate a cancel location procedure to the ISR activated related node entity the next time the UE attaches to the triggering entity.

7. A system for releasing bearer resources, comprising:

the trigger entity is used for sending a bearer deletion request message containing the reason information of the bearer to be deleted to the service gateway;

the service gateway is used for deactivating an idle signaling reduction ISR mode and deleting the bearer context related to the triggering entity if the local detachment is determined to be needed according to the reason information of the bearer needing to be deleted after receiving the bearer deleting request message; and if the complete detachment is determined to be required according to the reason information requiring the bearer deletion, the ISR mode is deactivated, a bearer deletion request is initiated to the packet data network PDN gateway, and the PDN gateway is triggered to execute a bearer deletion process.

8. The system of claim 7, further comprising: the trigger entity is further used for sending a detach indication to the ISR-activated related node entity, wherein the detach indication contains the reason information for deleting the bearer;

the ISR activated related node entity is used for deactivating an ISR mode if local detachment is determined to be needed according to the reason information needing to delete the bearer after the detachment indication is received; if the fact that the bearer needs to be deleted is determined to need to be completely detached according to the reason information needing to be deleted, deleting locally stored context information of the UE; and responding to the response message to the triggering entity.

9. The system according to claim 8, wherein when the triggering entity is a mobility management entity MME, the associated node entity activated by ISR is a serving GPRS support node SGSN;

10. The system of claim 7 wherein the triggering entity is configured to further store a detach type and a latest ISR activated active flag during the local detach procedure, and is configured to initiate a location update request procedure to the home subscriber server HSS when the UE attaches to the triggering entity next time, and trigger the HSS to initiate a location cancel procedure to the ISR activated relevant node entity.

11. A gateway device, comprising:

a local detach unit, configured to deactivate an idle signaling reduction ISR mode and delete a bearer context related to the trigger entity if it is determined that local detach is required according to the cause information of bearer deletion required after receiving the bearer deletion request message;

12. The apparatus of claim 11, wherein the complete detach unit initiates a delete bearer request to a PDN gateway to perform an IP-CAN session termination procedure.

13. A network device, comprising:

a first sending unit, configured to send the bearer deletion request message to a serving gateway, so that after receiving the bearer deletion request message, if it is determined that local detach is required according to the cause information that the bearer needs to be deleted, the serving gateway deactivates an idle signaling reduction ISR mode and deletes a bearer context associated with the network device, and if it is determined that complete detach is required according to the cause information that the bearer needs to be deleted, the serving gateway deactivates the ISR mode, initiates a bearer deletion request to a packet data network PDN gateway, and triggers the PDN gateway to perform a bearer deletion process.

14. The apparatus of claim 13, further comprising:

a storage unit, configured to store a detach type and a latest ISR activation activity flag when the serving gateway determines that local detach is required, and to initiate a location update request procedure to the HSS when the UE attaches to the network device next time, so as to trigger the HSS to initiate a location cancel procedure to a relevant node entity activated by the ISR.

15. The network device of claim 13, further comprising:

a second sending unit, configured to send a detach indication to a relevant node entity activated by the ISR, where the detach indication includes cause information that a bearer needs to be deleted;

a receiving unit, configured to receive a response message from the relevant node entity activated by the ISR.